The most common and natural human behaviours are often the most computationally difficult to understand. This is especially true of spoken language comprehension considering the acoustic ambiguities inherent in a speech stream, and that these ambiguities are exacerbated by the noisy and distracting listening conditions of everyday life. Nonetheless, the human brain is capable of rapidly and reliably processing speech in these situations with deceptive ease – a feat that remains unrivaled by state-of-the-art speech recognition technologies. It has long been known that supportive context facilitates robust speech perception, but it remains unclear how the brain integrates contextual information with an acoustically degraded speech signal. The four studies in this dissertation utilize behavioural and functional magnetic resonance imaging (fMRI) methods to examine how the normally functioning human brain uses context to support the perception of degraded speech. First, I have observed that text presented simultaneously with distorted sentences results in an illusory experience of perceptually clearer speech, and that this illusion depends on the amount of distortion in the bottom-up signal, and on the relative timing between the visual and auditory stimuli. Second, fMRI data indicate that activity in the earliest region of primary auditory cortex is sensitive to the perceived clarity of speech, and that this modulation of activity likely comes from left frontal cortical regions that probably support higher-order linguistic processes. Third, conscious awareness of the visual stimulus appears to be necessary to increase the intelligibility of degraded speech, and thus attention might also be required for multisensory integration. Finally, I have demonstrated that attention greatly enhances the processing of degraded speech, and this enhancement is (again) supported by the recruitment of higher-order cortical areas. The results of these studies provide converging evidence that brain uses prior knowledge to actively predict the form of a degraded auditory signal, and that these predictions are projected through feedback connections from higher- to lower-order order areas. These findings are consistent with a predictive coding model of perception, which provides an elegant mechanism in which accurate interpretations of the environment are constructed from ambiguous inputs in way that is flexible and task dependent. / Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2012-09-25 10:48:50.73

The present study investigated how knowledge of tonality is used in sight-reading by comparing sight-reading accuracy across three tonal constructs: major, minor and atonal. It was hypothesized that sight-reading performance would be the worst in instances with no tonal information, as participants would be unable to generate appropriate top-down expectancies to guide their sight-reading. To test this, twelve pianists sight-read major, minor and atonal versions of monophonic, homophonic and polyphonic excerpts. The results indicated that pianists performed the major excerpts with greater accuracy than the atonal excerpts. Furthermore, the errors made within the major excerpts were significantly biased towards diatonicism, and there was a global shift towards tonality in participants’ atonal performances, providing a clear demonstration of how pianists’ expectations might have contributed to their sight-reading performance. The diatonic bias was not found in the minor excerpts, suggesting that the minor hierarchy does exert as strong of an influence during sight-reading.

Zugl.: München, Techn. Univ., Diss., 2008

München, Techn. Univ., Diss., 2008

Zugl.: München, Techn. Universiẗat, Diss., 2008.

Studien som här sammanfattas är kvantitativ och börjar med en redogörelse av tidigare forskning inom ämnena, medarbetarskap, top-down – bottom-up, samt street level bureaucacy. Därefter redovisas den teoretiska referensramen som arbetet utgått från; Dochertys organisatoriska lärande. En svensk kommun bestående av omkring 10 000 medarbetare har använts som population till arbetet hos vilken en surveyundersökning genomförts. Syftet med studien var att undersöka relationen mellan lärande och medarbetarskap. Fokusområden har varit individens lärande inom organisationen liksom hur detta påverkat deras intryck av sitt medarbetarskap. Det resultat som framkommit visar att lärande är bidragande till ett välmående medarbetarskap. Slutligen skildras en analys av resultatet som sedan leder till en diskussion.

Doctor of Philosophy / Department of Psychological Sciences / Lester C. Loschky / Political videos are created as persuasive media, and at a basic level that persuasion would require that the videos guide viewer attention to the relevant persuasive content. Recent work has shown that filmmakers have techniques that allow them to guide where viewers look, and this guidance occurs even when viewers have very different understandings of the film. The current research tested if these attentional effects carry over to political videos, or if the top-down factors of attitude congruence and social vigilantism, belief superiority and the tendency to impress one’s “superior” beliefs on others (O'Dea, Bueno, & Saucier, 2018; Saucier & Webster, 2010; Saucier, Webster, Hoffman, & Strain, 2014), will break the ability of videos to guide viewers’ attention. Attentional selection was measured through participants’ eye movements, and memory encoding was measured through recall and recognition for both verbal and visual information. Three overarching competing hypotheses predicted different relationships between attitude congruence, social vigilantism, and visual attention and memory. The Tyranny of Film Hypothesis predicted that the videos would guide viewer attention, regardless of attitude congruence. This would result in similar eye-movements and memory for all participants. The Selective Exposure Hypothesis predicted that participants would avoid processing attitude-incongruent information. As a result, viewers’ visual attention would be directed away from attitude-incongruent information, and subsequent memory would be worse. Lastly, the Social Vigilantism Hypothesis predicted that people high in Social Vigilantism would engage more with attitude-incongruent information. Two experiments tested these hypotheses. The first was the Memory experiment (conducted online), and the second was the Eye movement experiment. In each experiment, participants watched a series of political advertisement and debate videos, and attitudes were measured to identify which information in the videos was attitude-congruent and incongruent. The Memory experiment showed some support for the Social Vigilantism Hypothesis, with People high in Social Vigilantism having better memory for attitude-incongruent information on certain memory measures. Conversely, the Eye movement experiment consistently showed strong stimulus driven effects in support of the Tyranny of Film, but also weaker attitude and social vigilantism effects that were independent of attitude congruence. Altogether, these results show dynamic video stimuli features are the best predictors of viewer attention and memory, but viewer attitude and social vigilantism have subtle top-down effects. The support for different hypotheses between the two experiments indicates the strength of top-down effects may depend on the format of the viewing experience, and specifically how much control the viewer has over the experience.

The passive perception of irrelevant actions can facilitate or interfere with the execution of one’s own actions, known as ‘automatic imitation’ (AI). For example, when one is pressing down on a button, reaction times (RTs) are faster when observing a finger depression (compatible action) and slower whilst observing a finger lift (incompatible action). This phenomenon has been attributed to the mirror neuron system and is thought to represent a laboratory model of spontaneous motor mimicry which facilitates social interactions. AI is typically reduced or absent when the observed movement is produced by a non-human agent. However, previous findings suggest that the magnitude of this ‘human bias’ can be modulated by top-down factors, such as attention and prior instructions regarding whether the movement was produced by a human or non-human agent. This thesis aimed to further examine the role of attention and belief regarding stimulus agency in automatic imitation. Participants were required to perform a pre-specified key press or release response to a diffuse yellow flash go signal. This response was either compatible or incompatible with the finger or object movement, which was presented simultaneously. AI was measured by subtracting compatible from incompatible RTs to calculate the compatibility effect. Experiments 1a, 1b, 2 and 7 focused on exploring the role of attention in AI. Experiment 1a revealed that the human bias is dependent on when the go signal occurs. AI was greater for the finger stimulus relative to the object stimulus when the go signal occurred during the movement, but not after the movement. It is suggested that attention to the movement is reduced when the go signal occurs after the movement. This implies that the human bias in AI is dependent on attention being directed towards the movement. Experiments 1b and 2 indicated that AI was removed if a visual dual task was added, but that AI remained and was greater when an auditory dual task was added. This indicates that AI was removed when the visual dual task competed for cognitive resources with action observation. The facilitation of AI when an auditory dual task was added suggests that the additional cognitive load may have occupied cognitive resources required for the inhibition of imitation. These findings highlight that AI is susceptible to attentional load, implying that AI is not a strongly automatic process. Experiment 7 explored whether the spread of attention modulates the magnitude of AI by comparing a ‘diffuse’ go signal to a ‘focused’ go signal which directed attention to the stimulus movement. Significantly larger AI effects were produced for the group of participants who saw the focused flash first, indicating that focusing attention on the spatial location of the movement increased AI, and furthermore that initially observing the focused flash ‘trained’ participants to pay attention to the stimulus movement in the diffuse flash condition. Experiments 3 and 4 examined why AI effects for non-human stimuli are more likely to be significant when trials are presented in separate blocks (e.g. human vs. non-human stimuli) as opposed to randomly mixed trials. It was hypothesised that this pattern of previous results could be due to less attention being drawn to stimulus differences when stimuli are presented separately as opposed to mixed with a block of trials. However, in both experiments, AI effects were present for the object stimulus in the group of participants who observed the block of finger trials first. This suggests that the prior observation of the finger movement caused a carry-over of human agency to the object stimulus. Experiments 5, 6, 8 and 9 directly explored the role of belief regarding stimulus agency in AI by instructing participants that the object movement was generated by a human finger movement. Experiments 5, 6 and 8 provided preliminary evidence that AI is affected by belief instructions, but the effects were weak or confounded by spatial stimulus-response compatibility (SRC) effects (i.e. compatibility effects based on spatial correspondence of the stimulus and response location). Experiment 9 was designed to differentiate imitative compatibility from SRC effects, thus providing a pure measure of imitative compatibility. Imitative compatibility was present for the object stimulus after the belief manipulation. This demonstrates that a human belief regarding stimulus agency of the object modulated imitative compatibility effects due to the top-down knowledge that the movement was human generated, and not due to increased attention and SRC effects. The presented work has provided multiple lines of evidence which demonstrate that so-called ‘automatic’ imitation effects are strongly susceptible to top-down influences, including attention and belief regarding stimulus agency. The current work could be used to evaluate top-down modulation of imitation in autistic populations, as it has been proposed that top-down modulation of the automatic imitation pathway may be atypical in autism.

According to the predictive coding approach to perception, the brain uses predictions based on previous experience to optimise perception, by allocating more computational resources to important or unexpected stimuli. Overall, predictions allow faster and more accurate recognition, but occasionally, when the prediction is incorrect, it may lead to a misperception. The aim of this thesis was to investigate the influence of top - down processes on perceptual decisions. I utilised misperceptions as a signature of those top - down influences and Signal Detection Theory to assess their size, type and direction. I used Electroencephalography to determine the stage of information processing at which different types of predictions influence sensory processing.The empirical studies are clustered around Topic 1: Influence of Predictions on Perception, Topic 2: Types of Predictions and Topic 3: Value as Modulator of Perception.Studies clustered in Topic 1 analysed and quantified the influence of predictions on perceptual decisions and showed that misperceptions can be triggered by wrong predictions only in very specific circumstances. In particular, misperceptions occurred only if there was some degree of correspondence between the wrong prediction and the sensory input. Otherwise, predictions were easily rejected, increasing the overall accuracy. I also demonstrated that misperceptions were most likely to happen in a window on the continuum of input quality where the stimulus - related uncertainty was highest. Topic 2 comprised experiments investigating different types of predictions and their interaction. Behavioural (but not EEG) results revealed interference between passive and active expectations. The early event related (ERP) components N1 and P2, as well as the P300, were all modulated by expectations. Expected events either increased or decreased the P300 amplitude, depending on whether the expected item was predictable and thus ignored, or awaited and thus flagged for further processing. This suggests that P300 might be an index of top - down resource allocation. Experiments within Topic 3 studied the influence of values, as examples of executive processes, on perceptual decisions, using either natural or acquired high - value stimuli. The results suggested that the process of recognition is adjusted in a top - down manner to account for the cost and benefit values related to different outcomes. The trade - off between processing time and accuracy is not fixed, but can be adjusted to optimise recognition in the task at hand. Furthermore, value can change the focus of perception, resulting in different elements of the sensory input being amplified or ignored. Overall, these results showed that misperceptions are 'intelligent mistakes' - a by - product of a top-down, prediction - based optimisation strategy that decreases the computational load, while increasing accuracy and improving the allocation of computational resources.

Purpose – The purpose of the study is to map out the top-down and bottom-up perspectives and investigate the information strategies on how it relates to daily operations in three case companies. To fulfill the purpose, the following three questions have been answered:   What approach do the organization have on information strategies and what  characterizes them? To what extent do the case organization use the information strategies?   What opportunities and difficulties do organizations see with the information strategies?   Method – To fulfill the purpose, a case study was carried out on three case companies. The empirical data has been collected through interviews and surveys. The theoretical framework together with the empirical data, has then contributed to achieving the purpose.   Findings – First the map out was conducted within three case companies and how the information strategies have been chosen in relation to the daily operations perspective. Based on the mapping, it has then been framed the potential possibilities and difficulties with the respective strategy choices and its implementation. Limitations – The definition of the information strategies within the study is defined as Top-down and Bottom-up and how the choice in how companies choose to coordinate and be responsible for tasks. The authors do not know whether the study can be adapted to the business of other organisations when mapping information strategies.   Keywords – information strategies, top-down, bottom-up, information flow, communication.